Which of the following is NOT a type of cornice?

The option identified as not a type of cornice is correct because "lookout cornice" is not a recognized term within architectural terminology related to cornices. Cornices serve to provide a decorative finish along the top edge of walls or roofs and can take many forms including specific designs meant for aesthetic appeal or structural function.

Box cornice refers to a boxed structure often built over the edge of a wall to conceal certain elements like gutters or to enhance the visual appearance of the architecture.

Bracket cornice involves decorative brackets positioned underneath a cornice to add both support and ornamentation, emphasizing the building’s style.

Pediment cornice is typically formed in a triangular shape, usually found above doors or windows, and serves both a structural and decorative purpose.

Understanding these definitions helps clarify why the other choices are indeed recognized types of cornices, while the term "lookout cornice" does not appear in standard architectural vocabulary.